11. The Judds
Essential Album: Greatest Hits
The mother-and-daughter act ruled the 1980s country charts. The Judds' traditional sound and raft of hits, including "Mama He's Crazy" and "Grandpa (Tell Me 'Bout the Good Ol' Days)," made them one of the most visible country acts of the decade.
12. The Nitty Gritty Dirt Band
Essential Album: Will the Circle Be Unbroken
The Nitty Gritty Dirt Band created music that could be appreciated by fans of folk, rock, and bluegrass. They borrowed from each, making roots music that left its imprint on both The Eagles and Alabama.
13. The Bellamy Brothers
Essential Album: The Best of the Bellamy Brothers
David and Howard Bellamy's breezy hit "Let Your Love Flow" struck the pop charts with gale-force velocity in 1976. They cemented their country credentials with "If I Said You Had a Beautiful Body Would You Hold It Against Me," which became a #1 country hit.
Essential Album: Lonestar
The silky harmonies of Dean Sams, John Rich, and Richie McDonald vaulted the country group to superstar status in the mid-1990s. Their ballads "Amazed" and "Tequila Talkin'" remain inescapable.
15. Brooks & Dunn
Essential Album: Brand New Man
"Boot Scootin' Boogie" did a lot to popularize line-dancing. The pair are at their most laid-back with the tunes "Neon Moon" and "My Maria." In addition to their work as performer, the duo were also highly productive songwriters.
16. Johnnie & Jack
Essential Album: For Old Times Sake
They weren't real brothers, but Johnnie Wright and Jack Anglin left their own stamp on the famed close-harmony duos of acts such as The Louvin Brothers. They didn't mind adding Latin flavor in songs such as "Ashes of Love." The group ended when Jack Anglin died in a car crash in 1963.
17. The Statler Brothers
Essential Album: Flowers on the Wall: The Essential Statler Brothers
The gospel quintet earned a secular hit with "Flower on the Wall" in 1965. Since then, the not-quite brothers have kept a toe in both the religious and secular worlds.
18. The Oak Ridge Boys
Essential Album: Gold
The Oak Ridge Boys began singing their take on gospel tunes in the late 1940s. They gained the biggest success in the '70s and '80s, and continued to active into the 2000s. Their secular hit "Elvira" won a Grammy in 1981.
19. The Mavericks
Essential Album: What a Crying Shame
As their name suggests, it's hard to pin down The Mavericks. Western swing, '60s pop, and Latin soul are fair game for building their intoxicating sound. After paying their dues for many years, they hit paydirt with 1994's multi-platinum What A Crying Shame.
20. Zac Brown Band
Essential Album: You Get What You Give
Formed in 2000, Zac Brown Band gained favor with their eclectic repertoire and summers songs like "Toes." Their wide range of influences gained the group followers from outside the usual pool of country listeners, helping to reinvigorate the format.
21. Big & Rich
Essential Album: Horse of a Different Color
John Rich and Big Kenny released their brand of hard-edged country in 2004. Rich was formerly in Lonestar. They started writing hits before coming into their own with the chart-toppers "Save a Horse (Ride a Cowboy)" and "Lost in This Moment."
Essential Album: Love on the Inside
Sugarland made a big dent on the country charts with their soulful vocal numbers and high-octane shows. The group's "steampunk" album The Incredible Machine divided fans over its bold rock sound. The duo continue to keep critics interested in following their next move.
23. Montgomery Gentry
Essential Album: Some People Change
Eddie Montgomery and Troy Gentry joined forces in 1999, and took country music in exciting new directions. Their hard-boiled tunes sound pure country even when they borrow the sounds of Southern rock and hip-hop.
24. Lady Antebellum
Essential Album: Need You Now
Lady Antebellum's self-titled debut yielded the #1 country single "I Run to You." Its successor, Need You Now, escorted the trio into the pop charts. Their silky emulsion of Pat Benetar pop and roots music make the threesome a commercial force to reckoned with.
25. The Highwaymen
Essential Album: Highwayman
This outlaw supergroup pooled the talents of Johnny Cash, Waylon Jennings, Willie Nelson, and Kris Kristofferson. They released three albums, resulting in posse renditions of Bob Seger's "Against the Wind" and Guy Clark's "Desperadoes Waiting for a Train."